Heretofore it has been well known to bond electrically conductive leads to the ends of rolled metallized film capacitors or the like. The conductive leads and/or the metallized film capacitor ends are pre-tinned and brought into intimate contact. Heat is then applied to the leads by a contact device such as a heated ram, soldering iron or the like to reflow the pre-tinned material to effect a bond.
Such a technique has proved most effective in the past. However, with the ever increasing miniaturization of such capacitors, heat dissipation presents problems. Heat transferred, by a soldering iron or other relatively massive members, to such a miniature capacitor, as well as the force exerted thereon, can destroy or severely damage the capacitor.
One proposed solution to the bonding of leads to miniaturized capacitors is the use of a laser. The laser appears particularly attractive since it inherently provides a non-contacting method of bonding wherein a carefully controlled amount of heat is applied to the joint interface. Furthermore, such a laser technique may be fully automated and designed to operate at high production rates.
Unfortunately, most leads that are to be bonded to the ends of the components are highly reflective of the laser light resulting in poor optical coupling efficiency. Additionally, when relatively planar articles are brought together, high spots on one or more of the articles result in poor physical contact which can create voids in the reflowed solder.